• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.110.2-110.2
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• 2012

We reported on antireflective ZnSnO (ZTO)/Ag bilayer and ZTO/Ag/ZTO trilayer source/drain (S/D) electrodes for all-transparent ZTO channel based thin film transistors (TFTs). The ZTO/Ag bilayer is more transparent (83.71%) and effective source/drain (S/D) electrodes for the ZTO channel/Al2O3 gate dielectric/ITO gate electrode/glass structure than ZTO/Ag/ZTO trilayer because the bottom ZTO layer in the trilayer increasea contact resistance between S/D electrodes and ZTO channel layer and reduce the antireflection effect. The ZTO based all-transparent TFTs with ZTO/Ag bilayer S/D electrode showed a saturation mobility of 4.54cm2/Vs and switching property (1.31V/decade) comparable to TTFT with Ag S/D electrodes.

• Transactions on Electrical and Electronic Materials
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• 제17권3호
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• pp.143-145
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• 2016

In order to find suitable source and drain (S/D) electrodes for amorphous InGaZnO thin film transistors (a-IGZO TFTs), the specific contact resistance of interface between the channel layers and various S/D electrodes, such as Ti/Au, a-IZO and multilayer of a-IGZO/Ag/a-IGZO, was investigated using the transmission line model. The a-IGZO TFTs with a-IGZO/Ag/a-IGZO of S/D electrodes had good performance and low contact resistance due to the homo-junction with channel layer. The stability was measured with different electrodes by a positive bias stress test. The result shows the a-IGZO TFTs with a-IGZO/Ag/a-IGZO electrodes were more stable than other devices.

• Transactions on Electrical and Electronic Materials
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• 제12권6호
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• pp.271-274
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• 2011

Screen-printed source and drain electrodes were used for a spin-coated and inkjet-processed zinc-tin oxide (ZTO) TFTs for the first time. Source and drain were silver nanoparticles. Channel length was patterned using screen printing technology. Different silver nanoinks and process parameters were tested to find optimal source and drain contacts Relatively good electrical properties of a screen-printed inkjet-processed oxide TFT were obtained as follows; a mobility of 1.20 $cm^2$/Vs, an on-off current ratio of $10^6$, a Vth of 5.4 V and a subthreshold swing of 1.5 V/dec.

• 한국전기전자재료학회논문지
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• 제28권7호
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• pp.433-438
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• 2015

Zinc tin oxide transparent thin film transistors (ZTO TTFTs) were fabricated by using $n^+$ Si wafers as gate electrodes. Indium (In), aluminum (Al), indium tin oxide (ITO), silver (Ag), and gold (Au) were employed for source and drain electrodes, and the mobility and the threshold voltage of ZTO TTFTs were observed as a function of electrode. The ZTO TTFTs adopting In as electrodes showed the highest mobility and the lowest threshold voltage. It was shown that Ag and Au are not suitable for the electrodes of ZTO TTFTs. As the results of this study, it is considered that the interface properties of electrode/ZTO are more influential in the properties of ZTO TTFTs than the conductivity of electrode.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.648-650
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• 2008

We used micro-contact printing for source and drain electrodes of OTFTs. The proper solvent of Ag paste and baking temperature were extracted for PVP gate dielectric and pentacene semiconductor. The mobility was 0.025 cm2/V.sec and on/off ratio was $2{\times}10^5$.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.597-600
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• 2006

The silver gate and source/drain electrodes for an a-Si thin film transistor were fabricated by the selective electroless plating (SELP) process. Relevant physical properties including taper angle, uniformity and resistivity are investigated. The Ag layer was about 150nm to 250nm thick, the resistivity less than $3{\times}10^{-6}$ Ohm-cm and the taper angle 45'-60' and the nonuniformity less than 10% on G2 substrates. The transfer characteristics with the Ag gate, and source/drain electrodes respectively possessed good field effect mobility similar to conventionally fabricated a-Si TFTs. This process provided low resistivity, low cost and ease of processing.

• 한국전기전자재료학회논문지
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• 제21권9호
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• pp.835-843
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• 2008

We have fabricated the source-drain electrodes for OTFTs by screen printing method and manufactured Ag pastes as conductive paste. To obtain excellent conductivity and screen-printability of Ag pastes, the dispersion characteristics of Ag pastes prepared from two types of acryl resins with different molecular structures and Ag powder treated with caprylic acid, triethanol amine and dodecane thiol as surfactant respectively were investigated. The Ag pastes containing Ag powder treated with dodecane thiol having thiol as anchor group or AA4123 with carboxyl group(COOH) of hydrophilic group as binder resin exhibited excellent dispersity. But, Ag pastes(CA-41, TA-41, DT-41) prepared from AA4123 fabricated the insulating layer since the strong interaction between surface of Ag powder and carboxyl group(COOH) of AA4123 interfered with the formation of conduction path among Ag powders. The viscosity behavior of Ag pastes exhibited shear-thinning flow in the high shear rate range and the pastes with bad dispersion characteristic demonstrated higher shear-thinning index than those with good dispersity due to the weak flocculated network structure. The output curve of OTFT device with a channel length of 107 ${\mu}m$ using screen-printed S-D electrodes from DT-30 showed good saturation behavior and no significant contact resistance. And this device exhibited a saturation mobility of $4.0{\times}10^{-3}$ $cm^2/Vs$, on/off current ratio of about $10^5$ and a threshold voltage of about 0.7 V.

• 한국정밀공학회지
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• 제31권6호
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• pp.497-504
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• 2014

The digital signage display is actively researched as the next generation of large FPD. To commercialize those digital signage display, the manufacturing cost must be downed with printing method instead of conventional photolithography. Here, we demonstrate a reverse offset printed TFT electrodes for the digital signage display. For the fabricated source/drain and gate electrode, we used Ag ink, silicone blanket, Clich$\acute{e}$ and reverse offset printer. We printed uniform TFT electrode patterns with narrow line width(10 ${\mu}m$ range) and thin thickness(nm range). In the end the printing source/drain and gate electrode are successfully achieved by optimization of experimental conditions such as Clich$\acute{e}$ surface treatment, ink coating process, delay time, off/set process and curing temperature. Also, we checked that the printing align accuracy was within 5 ${\mu}m$.

• Transactions on Electrical and Electronic Materials
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• 제16권3호
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• pp.139-141
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• 2015

Contact resistance of interface between the channel layers and various S/D electrodes was investigated by transmission line method. Different electrodes such as Ti/Au, a-IZO, and multilayer of a-IGZO/Ag/a-IGZO were compared in terms of contact resistance, using the transmission line model. The a-IGZO TFTs with a-IGZO/Ag/a-IGZO of S/D electrodes showed good performance and low contact resistance due to the homo-junction with channel layer.

• 폴리머
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• 제33권5호
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• pp.397-406
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• 2009

유기 박막 트랜지스터 (OTFTs)의 소스-드레인 전극을 스크린 인쇄를 통해 제작하였고, 전극용 페이스트로써 전도성 카본블랙 페이스트를 사용하였다. 전도성 카본블랙 페이스트를 제조하기 위해 서로 다른 분자량 및 고분자 사슬 구조를 갖는 2종류의 분산제(DB-2150, DB-9077)를 사용하여 분산제 함량(SOF; solid on powder, 10-40%)에 따른 카본블랙 밀베이스의 분산 특성을 검토한 결과, 분산제 함량이 증가함에 따라 분산 특성이 더 우수해 짐을 알 수 있었다. 전도성 카본블랙 페이스트를 제조하여 레올로지 측정을 통해 카본블랙의 분산상태 및 응집구조에 대해 검토한 결과, 분산제로 DB-2150을 사용한 페이스트들은 분산제 함량이 증가함에 따라 페이스트의 분산 특성이 향상되어 저장 탄성률(G')이 감소하였지만, DB-9077을 사용한 페이스트들은 카본블랙 사이의 상호작용에 의해 망목구조가 존재하였고, 분산제 함량이 증가함에 따라 카본블랙과 분산제간 또는 분산제간의 상호작용에 의해 페이스트의 저장 탄성률(G')은 더욱 증가하였다. 이러한 응집구조는 페이스트의 내부 저항력 (tacky)을 발생시켜 DB-9077을 사용한 페이스트들은 분산제 함량이 증가함에 따라 스크린 인쇄 적성이 좋지 못하였다. 하지만, 스크린 인쇄된 OTFTs용 소스-드레인 전극의 전기적 특성은 카본블랙 사이에 형성된 망목구조에 의해 카본블랙의 도전 경로(conduction Path)가 형성됨에 따라 DB-2150을 사용한 페이스트들의 OTFTs에 비해 더 우수하였다. 그러나, 2종류의 분산제를 사용한 페이스트 모두, 분산제의 함량이 증가함에 따라 카본블랙 표면을 감싸는 분산제 함량 또한 증가하게 되어 이로 인해 카본블랙간의 도전 경로 형성은 어렵게 되고 전극의 특성은 점점 열화되었다.